Keeping risk factors in check helped people with diabetes stave off dementia, new research from the U.K. indicated.
In a prospective study of nearly 90,000 participants, those with type 2 diabetes had an 88% higher risk for incident dementia compared with diabetes-free controls, reported Thomas van Sloten, MD, PhD, of Maastricht University Medical Centre in The Netherlands, at the virtual European Association for the Study of Diabetes (EASD) meeting.
However, patients with diabetes who had five to seven risk factors within the guideline-recommended target range — including nonsmoking, HbA1c levels, blood pressure, BMI, albuminuria, physical activity, and diet — did not have an increased risk for dementia compared with controls (absolute rate difference per 1,000 person-years 0.20; HR 1.32, 95% CI 0.89-1.95).
The risk for incident dementia only seemed to increase as patients ticked off more boxes for off-target risk factors:
- Four risk factors on target: HR 1.70 (95% CI 1.23-2.33)
- Three risk factors on target: HR 2.33 (95% CI 1.73-3.15)
- Zero to two risk factors on target: HR 2.42 (95% CI 1.67-3.52)
On top of that, patients who kept control of lifestyle-related risk factors also saw fewer changes in cognitive processing speed, executive functioning, and brain volume.
“Dementia is a devastating disease that is feared by many patients, their caregivers, and clinicians. However, the effect of current management of type 2 diabetes on the risk of dementia is incompletely understood,” van Sloten told MedPage Today. “Current management of type 2 diabetes consists of promotion of a healthy lifestyle together with adherence to treatment targets such as blood sugar control.”
“This multidomain management strategy in diabetes is effective in reducing the risk of cardiovascular disease, but the effect on dementia has been less clear,” he added. “We therefore wanted to investigate to what extent dementia in individuals with diabetes can be potentially prevented by targeting multiple risk factors.”
van Sloten noted that the “pathophysiology of type 2 diabetes-related dementia is likely determined by multiple etiologies, including large vessel disease, microvascular dysfunction, and neurodegeneration. Given the multifactorial nature of dementia in diabetes, we hypothesized that interventions targeting several risk factors and mechanisms simultaneously may be required for optimal preventive effects.”
“The seven selected risk factors in our study … have each been associated with one or more of these etiologies,” he added.
The analysis was based on data from the U.K. Biobank Study, a population-based cohort of participants ages 40 to 69, who were recruited from 2006 to 2010, and included 10,663 people with type 2 diabetes who were then compared with 77,193 controls. Diabetes was defined as self-reported diabetes, use of a glucose-lowering medication, and according to fasting plasma glucose. Those with prediabetes were excluded.
After a mean follow-up of 9 years, 1.4% of people with diabetes were diagnosed with incident dementia, while only 0.5% of controls received this diagnosis. Brain changes were measured via a 3T MRI, specifically assessing white matter hyperintensity volume, total brain parenchyma volume, and lacunar infarcts. Memory was measured with the Pairs Memory Test, and processing speed was measured with the Reaction Time Test.
As for the seven risk factors, guideline-recommended target ranges were as follows: HbA1c under 7%, blood pressure under 130/80 mm Hg, BMI of 20 to less than 25, absence of microalbuminuria or macroalbuminuria, at least 150 minutes/week of moderate-to-vigorous physical activity, a healthy diet defined as optimal by the American Heart Association score, and not smoking.
The researchers noted that they didn’t consider cholesterol level as a risk factor because the link with cognitive dysfunction and structural brain abnormalities “is inconsistent.”
The group didn’t see any interactions with age or sex in relation to the outcomes.
Some limitations to the study were that the cohort was largely comprised of middle-age, white individuals, and that the mean follow-up period was only 9 years.
Ultimately, these findings provide “important evidence for doctors to promote current multifactor risk factor treatment strategies in diabetes and to encourage adoption of healthy habits among their patients,” van Sloten said.